Call parking like feature

I’m implementing a feature where I want to place a call on hold from one phone, then be able to pick up another phone and call “**” to retrieve the held call. I don’t want to use the park application just yet. I’m just making a small hold over feature that kind of mimic parking until I migrate to a newer more capable version of Asterisk (I’m running 1.8.5 now).

Is there some way in the dailplan to fetch a list of all calls/channels that are on hold?